Method of making cold rolled disks



March 1933- G. L. KELLEY Er AL METHOD OF MAKING COLD ROLLED DISKS Fl G.2.

Filed June 2, 1928 INVENTOR. G- BUDD.

EDWARD EORGE KELLEY ATTO E Patented Mar. 14, 1933 UNITED STATES PATENTOFFICE GEORGE L. KELLEY AND EDWARD G.

BUDD, OF PHILADELPHIA, PENNSYLVANIA, AS-

SIGNORS 'IO BUDD WHEEL COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A GOR-PORA'IION OF PENNSYLVANIA METHOD OF MAKING COLD ROLLED DISKS Applicationfiled June 2, 1928. Serial No. 282,441.

Our invention relates particularly to those methods of making wheeldisks or articles susceptible of similar manufacture in which coldrolling is a principal part of the work done upon the blank. Work doneby processes of combined rolling and spinning from sheet metal or thinplate is frequently used in such processes. In cases where the reductionof section is very great or relatively great as compared with the normalsection of the blank, the gross amount of working of the metal is veryhigh.

The principal object of our invention is to evolve a method of workingmetal, such as sheet steel, in which the aggregate amount of cold workin the process at large may be as great as desired,

Other objects have to do with the provision of exaggerated grain growthin the metal at any stage of the process, the preservation of the finishof the center'of the disk independently of the working on the outerzones of the disk to reduce the section thereof, and a general economyof energy in the treatment at large. There are yet other objects both ofless and equal importance. The only other one We would mentionpreliminarily is the evolution of a disk produced in the main by coldworking and having when complete, all of those qualities most desirablefor the makingof wheel bodies by subsequent die drawing. This requiresthe physical characteristics of the final product to be those ofmaterials, particularly steels, found best for die drawing.

Our process consists primarily in the pre conditioning of the bank atany state of its reduction for substantial cold working by annealing theouter zone only to the exclusion of the inner zone. Stated from anotherpoint of view, it may be said to consist in the limitation of the higherranges of temperature to regions lying wholly without that region withinwhich exaggerated grain growth appears, and the while annealing otherportions, in this case the outer zone of the disk, at any temperatureswhatsoever which may be found to give most efiicacious annealing. Stillfurther and yet another point, our method consists in protecting thosepreviously diagrammatically an apparatus for carrying,

out this method.

Fig. 1 is a cross sectional view showing.

more or less diagrammatically a preliminary Working of a steel disk byrolling and spinning it from the center outwardly to taper andcircumferentially expand the same.

Fig. 2 is an axial cross sectional view showing a furnace with apartially worked disk produced by the operation directed in Fig. 1 inplace thereon.

Fig. 8 is a cross sectional detail, the section being taken on the line33.

Fig. 4 is a view similar to Fig. 1 showing the further working operationto which the disk is subjected after annealing, as by rolling andspinning it from the center outwardly to further reduce its section andexpand its periphery.

10 is the wheel disk. It is shown in Fig. 2 as already partly tapered,as by a cold rolling and spinning operation shown in Fig. 1. Thetapering process leaves a central zone a (Fig. 2) unworked, i.e., of itsoriginal thickness, one adjacent zone I) but slightly worked and oneouter zone 0, more originally worked. Only the center remains unreducedand of its original thickness. The metal as a result of this first stepof cold working of our invention is unduly hard.

lVe place the disk blank 10 upon the top of a central column 11 of thefurnace 12. The diameter of the central column at the top isapproximately equal to the diameter of the combined central unworked andhence unreduced zone a and the adjacent slightly worked zone 7) of thedisk blank. The furnace 12 is provided with outer walls radially spacedfrom and concentric with the colthan the external diameter of the disk10. Heat is applied by injecting flame through suitable burners througha tangentially projected aperture or apertures 13, and swirls aroundcolumn 11 in rotary contact with the under surface of the outer zone ofdisk blank 10 and from the open top of the furnace through the spacebetween the outer edge of the disk and the wall 12. The opened top ofthe furnace in the embodiment shown is substantially flush with theunder face of the disk 10. It may be otherwise in accordance with theheight of the outer wall 12. The bottom of the furnace is closed.

The heat of the furnace and hence of the outer zones of the disk isregulated to those temperatures which will produce the desired annealingof the outer zone of the disk, whatever these may be.

The massive central column 11 not only protects the center of the diskfrom contact with the flame, but also assists by its mass in keeping itrelatively cool through conduction. ater cooling through the centralmass is resorted to if desired. The relative adjustment of column 11 inarea, and mass and the adjustment of operating temperatures is such thatthe zone I) does not reach the minimum temperature at which exaggeratedgrain growth appears. Nor is the surface of the central portion marredin any way by the flame or heat.

The disk 10 having its outer zone so heated to proper annealingtemperature is then removed, and the annealing step completed by propercooling in any well known way.

Thereupon, cold work upon the disc blank 10 may be resumed in the outerzones 6 and 0 with impunity, as indicated by the additional rolling andspinning action depicted in Fig. 4. After such rolling the metal may bedie stamped to the desired form.

Certain classes of steel may be treated by our method before anyreduction of section is made with resultant advantage. In the main,however, the first step is an initial reduction of section in the outerzone I) and c, the second, an annealing of the outer zone while theinner zones a and particularly 6, are protected against heat which mightproduce exaggerated grain growth, and the completion of the product bycompleting the cold working of the outer zone I) and 0 to reduce thedisk to final section as shown in Fig. 4, but obviously the work may becarried out in any number of stages by repetition of ap plication of themethod which we have devised. By regulating this application withrespect to the amount of cold work done at each stage, the material ofthe disk blank may be kept in the very best condition for the work to beperformed upon it and the resulting finished product will be in the bestpossible condition for the die drawing whichis to give it contours toconstitute it a finished wheel body.

Not the least of the advantages of our invention it will be seen isgreat economy of energy. This takes place first in an economy of heatutilized for annealing in that by keeping the temperature of the centralzones down below the minimum at which exaggerated grain growth appears,the annealing of the outer zones is accomplished at the lowestpracticable temperatures. The apparatus of our invention is capable ofturning out the completely annealed disk each of one half or threequarters of a minute and the disk blank worked according to our methodcan be worked with less expenditure of energy because always in the bestcondition for working.

All of these modifications of our invention which fall within itsgeneric spirit are to be comprehended in the annexed claims.

\Vhat we claim as new and useful and deside to protect by Letters Patentis:

1. The method of forming a tapered disk which comprises annealing theouter peripheral portions of a disk blank while retaining the innerperipheral portions below the temperature at which exaggerated graingrowth appears and thereafter cold rolling the outer peripheral portionsof the blank.

2. The method of forming a tapered disk which comprises cold rolling adisk blank to an intermediate state, thereafter annealing the outerperipheral portions of the blank while retaining the inner peripheralportions 3810W the temperature at which exaggerated grain growth appearsand thereafter cold rolling the outer peripheral portions of the blank.

3. The method of metal working which comprises selectively annealing theportion of a blank which has been subjected to a maximum amount of coldrolling while shielding another portion of the blank to preventexcessive grain growth, and thereafter cold rolling said blank.

4. The method of metal working which comprises cold working a portionwhile leaving another portion of the work object unworked, in heatingthe worked portion while shielding the unworked portion from heat, andin annealing the again cold working the portion which has been worked,heated and annealed.

In testimony whereof we hereunto allix our signatures.

GEORGE L. KELLEY. EDWARD G. BUDD.

